In the most general terms, a musical instrument must perform two functions. It must generate sounds of sufficient volume to be heard assuming an acceptable tone, and it must provide means for these sounds to be manipulated in a manner which accurately represents the musical expression of the player. An instrument serves as a link in a chain, or loop, which begins in the player's mind as a musical concept, is physically transferred to the instrument and returns to the ear as musical expression. It will be appreciated that an instrument will be most satisfactory when it accurately expresses the player's original concept. To this end and of critical importance to an instrument's success, is its interaction with the chosen means of manipulation, be it the hands, feet or mouth of the player. A stringed instrument is played by the hands, and the manner in which the hands "fit" the instrument is one primary concern in the instrument's structure.
A stringed musical instrumentt commonly consists of two parts, a body and a neck, which are joined together to form a whole.
The neck of a stringed instrument such as a guitar, banjo, violin or the like supports one end of a set of tensioned strings, and provides the means for the player's hand to manipulate the strings to form various nodes and corresponding pitches.
The body of the instrument supports the other end of the strings and serves as a soundbox or resonator.
Various stringed instruments are presently available which can selectively produce sounds at different frequencies. In general, sounds in a stringed instrument are produced by causing the strings tto vibrate at a resonant frequency. It is well known that a string of a given length supported at its ends and under tension will vibrate at a specific frequency when excited, producing a single tone. It is also known that if the string is prevented from vibrating at a point along its lenglth, a node will be established at that point and the string will vibrate at a new frequency producing a different tone.
In instruments such as guitars, mandolins and other instruments of the same family, strings are held under constant tension above the instrument nbody and the neck extending from the body. A bridge on the body and a head on the neck provide primary support points or nodes for the strings which may be under different tensions.
A different tone can be produced on each vibrating string by restricting the movement of a string (i.e. forming a node) at any point along the length of the string. The effective shortening of the string is usually accomplished by utilizing a fingerboard or fretboard on the neck beneath the strings and by depressing the string against the fretboard at a single predetermined point. The initial mode of vibration will thus be suppressed and a new mode or tone produced. The fretboard is normally provided with a plurality of frets which are ridges extending from the surface of the neck to facilitate the formation of a nodal point transverse to the major axis of the neck. The frets are precisely spaced to provide the correct nodal distance between a fret and the bridge to produce a desired pitch.
The body of a stringed instrument supports the neck and the other end of a set of tensioned strings, and provides the means for increasing the volume of the tones generated by the vibrating strings and providing a characteristic timbre or acoustic quality to the sound thus created.
Acoustic guitars rely on a body cavity to cause resonant tones to be produced in the volume of air contained within the cavity and by coupling the vibration of the strings to the body through the bridge and neck. The shape and construction of a guitar body will determine its characteristic timbre by enhancing or diminishing responsiveness to certain frequencies of tone. The volume of air in the cavity will affect the loudness of the instrument, and to some degree the timbre, by effecting a greater or lesser efficiency in transferring energy from a vibrating string into vibrations in air.
The electric guitar utilizes an electromagnetic pickup supported by the body of the instrument which is usually constructed of a solid piece of material, with no air volume contained within. While the electromagnetic pickup is primarily responsible for the volume and timbre of the electric guitar, the body shape and density nonetheless affect timbre by enhancing or diminishing responsiveness to certain frequencies of string vibration.
The guitar, and similar stringed instruments, consist as stated hereinabove, of two separate parts, a body and a neck, which separately perform the two functions of a whole musical instrument, the body producing tones of sufficient volume to be heard, the neck providing means for the manipulation of those tones.
Bringing the two parts of a stringed instrument together to form a functional whole is not without its problems. The traditional geometry as developed in the prior art is reasonably well known.
The body consists of a top and sides and aback to which s joined a neck. The neck comprises a heel joined to the body and at the opposite end a head. The body is shaped into two round bouts, separated by a narrow waist and includes a centrally located soundhole.
A fretboard mounted to the surface of the neck and body has a precise relationship to the string's length, called scale length, such that the twelfth frett will always be at the midpoint of a scale length. A bridge at one end and tensioning machines and a nut at the other end of the fretboard secure the strings and define the length.
The neck and fretboard of a traditional guitar join the body at the twelfth or fourteenth fret from the nut so that the guitar, held with the waist resting on the leg of the player, balances in the player's hands, with one hand near the bridge and the other hand able to reach the end of the fretboard near the head. If the neck joined the body at a higher fret the palyer could not easily reach the notes at the end of the fretboard.
Most guitars have 19-24 frets, with generally at least seven frets overlying the body. Since it is desirable to have access to as many notes as possible, a portion of the upper trebel bout of the body is frequently cut away to allow the hand to move along the treble edge of the neck so as to reach those frets lying over the body. As little of the bout is cut away as possible to avoid diminishing the acoustic properties of the instrument. In this document, when cutaway is spelled as one word, it will refer to the reshaped upper treble bout; when spelled "cut away" it will be used as a verb.
The most serious problems in prior art devices have to do with balancing the conflicting aims of the two functions of a musical instrument--acoustic response and playability. In many prior art instruments a certain amount of playability is sacrificed so as to avoid diminishing acoustic response. Specifically, the body of prior art instruments interferes with the correct positioning of the hand on the neck when playing the highest frets, those which lie over the body of the instrument.
It will be apprciated that the expeditious manipulation of the strings requires critical positioning of the hand. Any change or interference with the hand position will detrimentally affect the facility with which a player can manipulate the strings of the instrument, and will affect the ultimate usefulness and function of the instrument. To fully understand the scope of this interference, it is necessary to precisely define correct hand position.
The player plucks the strings of the instrument near the bridge with one hand and stops them at various frets on the neck with the fretting hand. In order to play with facility the hands should follow the prope form or hand position rules. For the "fretting hand" the generally accepted rules are:
a. The fingers shall play with as little tension as possible. PA1 b. The fingers shall lay across the top portion of the enck perpendicular to the longitudinal axis of the neck (parallel to the frets). PA1 c. Any individual finger should occupy one fret so that four fingers usually occupy four adjacent frets. PA1 d. The thunb should rest on the back of the neck, perpendicular to the axis of the neck, and parallel the fingers. PA1 e. The thumb should be positioned behind or between the position of the first and second fingers, which is to say the plane, perpendicular to the axis of the enck, formed by the thumb should not fall outside the planes, perpendicular to the neck axis, formed by the first and second fingers. PA1 f. The thumb should grasp the neck at a certain point across the neck's width, that point to be determined by the following method: PA1 The thumb should grasp the neck at this point, approximately three-fourths across the neck toward the bass edge. Note the tip of the thumb is approximately even with the bass edge of the neck (see FIG. 17). PA1 g. Though the fingers may move across the width of the neck to finger one or several strings, the thumb will not generally move (except longitudinally) and will continue to grasp the enck at approximately the same location, so as to provide a "point at reference" for the constantly moving fingers. PA1 h. The wrist should not be bent inward, but should be straight.
The fingers should lay across the top of neck, or fretboard, so that the tip-most knuckle joint of the first finger is over or slightly inside the lowest pitched string, the handheld in a "U" shape.
These rules are based on the fact that it is the thumb which provides a "fulcrum" for the fingers, and that when the thumb is allowed to oppose the fingers in a comfortable and natural position, the leverage applied by the fingers will be most effective and facile.
It should be noted that some players adopt an altered hand position with respect to these rules, where the thumb grasps the neck further toward the bass edge, so that the tip of the thumb extends past the edge (see FIG. 18). Facility is somewhat diminished in this position, yet it is possible to play when grasping more of the neck. It is, however, virtually impossible to play with facility when the thumb is grasping less than half the neck's width.
A consideration that comes into play is that the humand hand comes in various sizes. These hand position rules then naturally assume that the references only apply when the hand is graspig an appropriately sized neck.
Instrument necks come in a variety of lengths, widths, and thicknesses to accommodate various hands. While the present invention necessarily is referenced to a "standard" consisting of the human hand, it is intended that the reference be made appropriately, i.e., if the fingers on any given hand comfortably and naturally occupy the fretboard on the upper surface of a neck, then the thumb will comfortably and naturally oppose the fingers on the lower surface of the same neck.
A serious disadvantage to all prior art instruments is their inability to allow proper hand position to be maintained throughout the length of the fretboard, causing significant difficulty in playing certain frequencies or tones. This disadvantage is caused by two factors in the construction of these instruments.
The first factor relates to the traditional construction of the heel portion at the base of the neck. The heel is an extension from the underside of the neck, at the base thereof, to attach the neck to the body and to provide support for the neck. The fretboard usually extends beyond the base of the neck and onto the body of the instrument, thereofre, the production of high-frequency notes (corresponding to relatively short nodal distances on the string) requires the depression of a string, to create a node, at a point on the fretboard or neck which is directly above a portion of the heel. The end of the heel prevents the thumb from assuming a correct position opposite the fingers which causes the entire hand to assume a contorted, incorrect position. The distorted position results in a decreased facility in playing the higher frequency tones relative to notes played on other portions of the neck where proper hand positions are easily achieved.
A second factor relates to the shape of the body of acoustic guitars and other acoustic stringed instruments. These instruments rely on a body cavity to "create" the loudness and timbre of the instrument. The traditional shape of the body itself interferes with the correct positioning of the hand on the fretboard position which lies over the body.
The problem is how to improve the second function of a musical instrument (playability) without negatively affecting the primary function (acoustic response). It would be relatively simple to extend the playable range of an instrument by simply cutting away more of the body and lengthening the neck, if one were willing to sacrifice the characteristic sound. It is desirable to improve the playability of the instrument without changing the sound.
Complicating this esoteric problem are mechanical considerations which relate to structural integrity structure must bring together playability and acoustic response in one instrument, ideally without one aspect diminishing the other. The acoustic response of an instrument is greatly improved by making the body light and therefore more responsive to the oscillations of the strings. The strings exert a great amount of tension (100-250 ft/lbs) and dimensional stability is enhanced by massive, solid construction. The neck should be as stable as possible to resist deformation caused by string tension. The fretboard must be very straight and level so that the strings may be set as close to the neck as possible, reducing the bending moment generated by the strings.
In conventional guitar designs, the top, sides and back of the body are connected to a heel block, the heel block is then connected to the heel of the neck. Thus, the heel block functions as an intervening member between the body of the instrument and the neck. The fretboard is applied over these elements, typically extending over the neck, the heel block and a portion of the top. Thus, the fretboard is supported by three distinct individual structures. Lying partly over the neck and partly over the body and heel block, the fretboard is frequently distorted by differing expansion and other internally generated stress in the members supporting it. The fretboard, therefore, does not maintain linear alignment.
The neck of such an instrument is usually provided with a truss rod tensioned between the free end of the neck and the heel of the neck. The truss rod serves to counteract the torque on the neck generated by the stringsn so that a flat surface is maintained for the fretboard. Since the fretboard typically extends beyond the heel of the neck, over the heel block and over an unsupported portion of the top of the body, the truss rod cannot maintain a substantially planar surface for mounting the fretboard. Thus, the fretboard may be subject to bending along a portion thereof not directly supported by the neck.